Improvement in forge-furnaces



HOT CHKISS & SHATTUCK.

Refining Iron and Steel.

No. 58,346. Patented Sept. 25, 1866.

N4 PETERS, FhnRu-Llhugnplwr, Washingium D. Q

UNITED- STATES PATENTOFFIGE.

BENNET HOTCHKISS, OF NEW HAVEN, AND HENRY SHATTU'CK, OFVHA'M- DEN,CONNECTICUT, ASSIGNORS TO BENNET HO'lCHKlSS.V

IM PROVEM-ENT IN FO RG E-FU RNACES.

Specification forming part of Letters Patent No. 58,346, dated September25, 1866.v

To all whom it may concern;

Be it known that we, BENNET llogrcnirrss, of'New Haven, and HENRYSHATTUCK, of Hamden, both in' the county of New Haven and State ofConnecticut, have invented certain ,new and useful m'provements'in Furnaces for Heating Metal; and we do hereby declare'the following, whentaken in icon-nection with the accompanying drawings and the letters ofreference` marked thereon',` to be a full, clear, and exact descriptionof the same, and which said drawings #constitute part of this`specification, and represeli?, in4

Figure 1, a`side elevation. Fig. 21's a plan. Fig. 3 is a longitudinaland`vertical section on a line in the rear of the frontwall. r

Qur invention has reference .tothe following particulars, which areintended to adaptthe heatingfurna'ce for general use in blacksmithshopsand in establishments where metals are worked: First, in combiningtogether the or` dinary forge with a reverberatory furnace, the heat ofthe latter being derived'from the same fire which is employed in thefurnace; second, in a better means for cooling the furnacedoors toVprevent the injurious elfe-cts of heat upon them by the use ofa'current of air, which may also, after it has performed this oiiice, be

lused for accelerating the fire-draft; third, in

interposing between the'workman and the fire, when the furnace-doorsopened, an air-blast to keep the Haine and gases back from the face ofthe workman fourth, in employing the waste heat for raising thetemperature of a body of waterandapplying the vapor to stimulate'combustion 'in the furnace; and, finally, lfifth, in 'employing the4same waste i heat, in the courseof its exit tothe chimney,

to raise the temperature of a bodyof air surrounding the smoke-flue,andinapplying vthe same for increasing the iiredraft.

. In the accompanying drawings, B represents the forge or furnace, ofwell-known construction,- 'provided withgrate-bars a a a, and with achute, B,through which the coals are introduced. With this furnaceiscombined a second chamber, C, separated from t-he first bya transversepartition, Ij. This partition should be of sufficient height to confinethe coals within the gratessurface, but should not be. so high as toobstruct the iiames from pass- Vresult of this combinatiori of these twoclasses of, furnaces, the-same fire which, bydirect action is made toheat metals in the first chamber, is, by ythe reverberatory principle,made valso available in the second chamber; and this second chamber can,if desired, be as readily constructed with a dome or arched roof, forbetter reliecting' :the heat, as with the tlat roof shown. 1 v A VlEachof the furnace-chambers 1s providedv withea door, E E', operated by alever and trea'dle in the usual way. We have introduced, however,- animprovement inthe method of preventing them from becomingundulyheatedwhich is as follows: rIhe doors are madewith outer and innerplates, `between which is an air-space. An air-blast is introduced intothis space by means of the nozzle which may be connected by a iiexibletube with asuitable bellows for the purpose. An

aperture in the edge )feachv doorallows the space between the outer andinner plates to communica-te with an opening under the gratebars bymeansof channels appropriate to each'door, made for thepurpose in a'projecting vertical piece, G, upon the fi'irnaeefront,

the edges of which projecting piece also furnish one of the two guidesto' each door, lateral open-ings 'bein-g made in the same, conimunicating with the vertical channels and corresponding with t-he lateralopenings in the edges of the doors, so that the blast, after it hasperformed its office of cooling the doors, is conducted under the fire,to increase the draft. y Y

' VVe'deem it advisable, also, (though a good 'effect may-be produced byconstructing the doors with simple double plates and an interveningair-space, as described,) to .interpose between the outer and innerpla-tes ofthe doors a wall of plaster-of-paris, soap-stone, or othernon-conductor of heat,- leaving air-spaces between each side of the sameand the door plates,'for the circulation of the blast` of air which isto be introduced. This arrangement will in'snre a greater degreeofdurability to the .doors`, and need not at all interfere with thearrangement described for conducting theblast .underneath thegrate-bars.

A similar and perhaps as useful effect, with- -ont' the aid of a blast,can be produced by making the doors of simply an outer and innermetallic shield or plate, separated from each other the usualvdistance'by stud-bolts,-the outer plate being perforated with holessufficient in number and size to allow the outside air to enter, and,after cooling the plates, be drawn, by the method already describcd,intothe furnace.

-In this latter arrangement it will be necessary to have a chimney ofsuflicient height to cause a draft powerful enough -for the purpose, andthen, in addition to the principal effect designed, there will be theincidental advantage obtained ot' a means lfor 'Ventilating theatmosphere ofthe room.

lsuitable and convenient means, is connected with an air-blast. i Thispipe has a longitudinal slit cut in one side, which is covered, when theblast is not required, by the sleeve H', f1tted to turn on the pipe H.This sleeve has also a similar slit cut inuits side, so that when thesleeve is turned on the pipe far enough to cause. the two slits tocorrespond a blast of air will be directed against the furnace-door.

This device is, in effect, an ordinary stop-v cock, and may be variouslyarranged to let on or cut off the lilast, as desired and while thedevice itself is well known, ythe application of it for the purposesdescribed is both novel and useful.

It has already been stated that the aperture b in thereverberatorychamberis intended for the escape of the smoke and gasesgenerated by the combustion of the fuel in the furnace A. Inasmuchas alconsiderable amount' of heat will also at the same time pass off, it isdesirableto utilize the saine as much as possible. Y f

The aperture l is connected by a smoke-pipe, I', with the iue J',arranged, by'preference, beneath the surface of the ground and leadingto the chimney.y This smoke-pipel is surrounded" by a close cistern, K,partially filled with water. There is a pipe,` d, near the top of thiscistern, above the water-line, leading to a point underneath thegrate-bars, through Which the vapor from the water, as the temperatureof the `latter is raised by the heat from the smokel pipe I, Will bepermitted to pass intothe furnace and stimulate combustion.

We also, for the purpose of further augmentling the. draftautomatically, surround the ground-ilue..l' with a jacket or secondpipe, L, between which and the outside of the flue-pipe is an air-space.It is evident' that the air in this surrounding space will soon becomeofthe same temperature, or nearly so, as the metal which composes thesmoke-flue. This heated air is also discharged underneath the gratebarsby means of v,a pipe, e,- conveniently arranged, a constant circulationbeing maintained by means of a supply of col air, which isadmitted intothe vspace through suitable' openings made -for the purpose, andcommunicating in any.convenient-way with the atmosphere.

Instead of surrounding the flue completely with the airchamberthesameeffect iny kind, thoughl less indegree, will be produced by par-'tially surrounding it with such chamber-as,

tor instance, where the cross-section of the flue is rectangular insteadof circular, the au chamber may be arranged along the'top or one or moreof its sides.

We do not mean to limit 'ourselves to the precise construction andarrangement'of the several parts asdescribed, but mean to include allmere variations of form, structure, and arrangement accomplishing thesame ef- .fect by substantially equivalent means' What iveclaim as our`invention, and desire to secure by Letters Patent, is

1. Combining a forge, A,'Witl1v a reverberatory furnace, C, in themannersubstantially as described, for the purpose' specified.

2. Applying a current of air, whether set in motion by an artificialblast or by the chimney-draft, to cool the furnace-doors and to furnisha draft to the fire, in the manner subas described, with the furnace A,for the purpose of converting intol vapor a body of Water by the wasteheat of the furnace, and applying such vapor to stimulate combustion,substantially asset forth.

5. Combining with the escape-fine J a space,

L, for the circulation of air, and connecting the same with the furnacefor-aiding the draft of Y the iire, substantially as described.

BENNET HOTCHKISS. HENRY SHATTUOK.

Witnesses:

J oHN E. EARLE, J oHN W. SHUMWAY.

